1. Field of the Invention
The present invention relates to a semiconductor device with a contact structure, and more particularly to a thin film transistor array panel including a contact structure and a manufacturing method thereof.
2. Discussion of Related Art
A typical semiconductor device has multiple layers of wires interposed between interlayer insulating layers. It is common that the interlayer insulating layers are made of materials with low permittivity to minimize the interference between signals flowing through the different wires, and different layers of wires transmitting the same signals are electrically connected to each other through contact holes provided at the interlayer insulating layers.
The interlayer insulating layers include an organic insulating layer with low permittivity, which is commonly formed by spin coating. When the structure underlying the organic layer has a steep height difference, the organic material is localized onto a specific area during the spin coating, thereby causing poor surface uniformity of the organic layer and the disconnection of a wire formed on the organic layer. In addition, for a liquid crystal display (“LCD”), particularly for a reflective type LCD displaying images by reflecting external light and for a transflective type LCD operating both in a reflective mode and a transmissive mode, this deteriorates display characteristics.
At present, an LCD is one of the most widely used flat panel displays. An LCD, which includes two panels having field-generating electrodes and a liquid crystal layer interposed therebetween, controls the transmittance of light passing through the liquid crystal layer by realigning liquid crystal molecules in the liquid crystal layer with voltages applied to the electrodes. Among these LCDs, the most commonly used one provides at least one field-generating electrode on each panel and includes thin film transistors (“TFTs”) switching the voltages applied to the electrodes.
Generally, a panel with TFTs (“TFT array panel”) includes, in addition to the TFTs, signal wires including gate lines transmitting scanning signals and data lines transmitting image signals, and pixel electrodes electrically connected to the gate lines and the data lines via the TFTs.
A pixel electrode of a reflective type LCD or a transflective type LCD includes a conductive reflecting film, which preferably has embossment for increasing the reflecting efficiency to improve display characteristics. The embossment of the reflecting film is formed by providing an organic insulating layer with unevenness under the reflecting film.
However, the stepped height of the organic insulating layer due to the steep height difference of the underlying structure gives the poor profile of the unevenness of the organic insulating layer, thereby causing the non-uniform embossment of the reflecting film to generate strains in a screen.